Optical disk having sequentially numbered sectors and logical tracks formed by a series of 2n sectors, and disk drive apparatus for using such an optical disk

ABSTRACT

An optical disk has a recording region divided into zones, each zone including a number of adjacent physical tracks. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sequentially numbered sectors. A logical track includes a series of 2 n  sectors, n being an integer.

This application is a divisional of application Ser. No. 09/148,798filed on Sep. 4, 1998 and now is U.S. Pat. No. 5,953,309, which is adivisional application of application Ser. No. 08/914,782, filed Aug.20, 1997 and issued on Oct. 20, 1998 with U.S. Pat. No. 5,825,728, whichis a divisional application of application Ser. No. 08/718,263, filed onSep. 20, 1996 and issued on Feb. 10, 1998 with U.S. Pat. No. 5,717,683,which is a divisional application of application Ser. No. 08/128,193,filed Sep. 29, 1993 and issued on Jan. 7, 1997 with U.S. Pat. No.5,592,452, the entire contents of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

The present invention relates to an optical disk permitting reading andwriting of data while being rotated at a constant angular velocity, andmore particularly to an optical disk having a recording surface dividedinto a plurality of zones, with higher frequency clocks being used toaccess the more outward zones of the disk so that the recording lineardensity is substantially identical between the outer and inner zones.

The present invention also relates to an optical disk which containsdifferent types of recording media for the respective zones, and inwhich the types of the respective zones can be altered during use of thedisk.

The present invention also relates to an optical disk drive device usedfor writing in and reading from the above-mentioned optical disks.

Known optical disks of the type having a storage capacity of 1 GB oneach surface have a format proposed in ECMA/TC31/92/36. According tothis proposal, the recording surface of the optical disk is divided intoa plurality of zones equally, i.e., such that the numbers of thephysical tracks in the respective zones are substantially equal. Thenumber of zones depends on the size of the sector. If each sectorconsists of 512 bytes, the number of the zones is 54. If each sectorconsists of 1024 bytes, the number of the zones is 30.

Each physical track has an integer number of sectors. The number ofsectors in each track is constant throughout each zone. The number ofsectors in each track is larger in more outward zones.

The optical disks that are available are either those of the R/W(read/write or rewritable) type which permit writing and rewriting asdesired, and those of the WO (write-once) type which permit writing onlyonce after fabrication, and those of O-ROM (embossed) type in which datais written at the time of fabrication, by embossing, and which do notpermit subsequent writing.

The number of sectors in each physical track differs from one zone toanother, as described above. A complex algorithm is needed for indexingthe physical location of the target sector when for instance the opticaldisk is used as a SCSI device, and is supplied with linear(consecutive-integer-numbered) logical addresses. Moreover, the datafield in each sector in an innermost physical track of a certain zoneand the header field in each sector in an outermost physical track ofanother zone next to and inside of the first-mentioned zone may beadjacent to each other, with the result that crosstalk from the headerfield may degrade the quality of the data read from the data field. Thisis because the information in the header field is written in the form ofpit (embossment) and has a greater degree of modulation, causing greatercrosstalk, while the information in the data field is magneto-opticallywritten and has a smaller degree of modulation. In this regard it isnoted that within each zone, header fields in all the tracks areradially aligned and data fields in all the tracks are radially aligned,so that a header field and a data field will not be adjacent to eachother.

It is also desired that recording areas of the R/W type, of the WO typeand of the O-ROM type be co-existing in a single disk to expand theapplication of the disks. Previously, optical disks of the P-ROM type,in which the recording areas of the R/W type and the recording areas ofthe O-ROM type coexist, were available, but no other combination ofrecording area types have been known.

SUMMARY OF THE INVENTION

An object of the invention is to provide an optical disk which enablesquick indexing of the physical location of the target sector responsiveto a given address.

Another object of the invention is to provide an optical disk permittingmixed presence of recording areas of different types.

A further object of the invention is to provide an optical disk drivedevice used for such optical disks.

According to a first aspect of the invention, there is provided anoptical disk including a recording region, physical tracks in saidrecording region each corresponding to one revolution, said recordingregion being divided into a plurality of zones by one or more circularboundary lines centered on the center of the disk, each zone including aplurality of physical tracks adjacent to each other, wherein an integernumber of sectors are provided in each physical track, the angularrecording density is higher in the more outward zones such that thelinear recording density is substantially constant throughout therecording region, and logical tracks are formed of a predeterminednumber of sectors, independent of the physical tracks.

With the above arrangement, each logical track is formed of sectors,independent of the physical tracks, and the number of the sectors ineach logical track is constant throughout the recording region,regardless of the radial position of the sector within the recordingregion, so that the conversion between the logical track and sectoraddresses read from the disk, at the sectors being accessed by theread/write head, and the linear logical addresses (one-dimensionaladdresses, or addresses represented by consecutive integers) suppliedfrom a host device is easy, and the grouping and defect management areeasy.

The addresses written in headers of the sectors in the logical track inwhich data are actually recorded, including substitute sectors used inplace of defect sectors, are preferably consecutive to furtherfacilitate the conversion between the logical track and sector addressesread from the disk and the linear logical addresses supplied from thehost device.

The difference obtained by subtracting the number of logical trackscorresponding to each zone from the number of logical trackscorresponding to another zone adjacent to and radially outside of eachzone is preferably constant.

With this arrangement, the address management of the disk isfacilitated, and the number of the logical tracks in the zone inquestion can be determined through integer calculations, withoutreferring to a table for address conversion, and the determination ofthe target sector during seek operation can be easily made.

The number of the physical tracks of zones adjacent to each other arepreferably made equal by providing sectors in which data is notrecorded.

With this arrangement, the calculation for determining the number oftracks to be traversed for accessing the target track is easy, and themanagement of the physical location is easy.

Addresses of the sectors in the tracks in which data is not recorded maybe assigned independently of the addresses of the sectors in the tracksin which data is recorded. Similarly, addresses of the sectors in thetest track in each zone are assigned independently of the addresses ofthe sectors in the tracks in which data is recorded. With thisarrangement, management of the tracks in which data is not recorded andthe test tracks is facilitated. The logical track and sector addressesare of consecutive values, so that the address management of therecorded data is facilitated. Access management of the test tracks isalso facilitated.

The difference obtained by subtracting the number of sectors in eachzone in which data is not recorded from the number of sectors in anotherzone adjacent to and outside of said each zone and in which data is notrecorded is preferably constant.

With this arrangement, the number of the sectors in each zone in whichdata is not recorded can be determined through simple integercalculations, without referring to a table, and the address managementof the disk is easy.

Data may not be recorded in the outermost and innermost physical tracksin each zone. This arrangement avoids crosstalk at the boundary betweenzones. That is, the header fields are not necessarily aligned radiallybetween different zones, and the header fields and the data fields oftracks adjacent to each other and belonging to different zones may beadjacent to each other. However, by the above arrangement in which theoutermost and innermost physical tracks are not used for recording data,the tracks in which data is recorded are separated from the tracks of adifferent zone, by at least one track in the same zone and in which datais not recorded, so that crosstalk is substantially eliminated.Degradation in the quality of data or disorder in tracking can thereforebe prevented, and more reliable data recording is achieved.

At least one of the physical data in each zone may be a test track usedfor adjusting of recording power. With this arrangement, the recordingpower can be adjusted for each zone, and the reliability of therecording can be further improved.

Defect management may be effected for each zone. With this arrangement,even where a defective track is found, it can be substituted for by atrack within the same zone, and it is not necessary to switch the clockfrequency while accessing the substitute track. As a result, addressmanagement for controlling the hardware depending on the actual physicallocation (where the read/write head is accessing), e.g., for switchingthe clock frequency, and defect management can be achieved in common, sothat the address management is achieved with a high speed.

Each logical track may be composed of 2^(n) sectors, with n being aninteger. With this arrangement, the addresses of the sectors arerepresented by consecutive integers, i.e., they are one-dimensional, sothat the calculation of the addresses of the sectors is easy.

An address of each sector may be written 2^(m) times, and an ID may beadded to the address at each occurrence to indicate the order of theoccurrence. With this arrangement, the addresses each formed of thetrack address, the sector address and the ID, are linear, or arerepresented by consecutive integers. Accordingly, the formatter used forformatting such a disk can be formed of a counter. Moreover, the sectoraddresses can be determined by counting up 2^(m) times. Theconfiguration of the formatter is therefore simple.

An address for each sector may include a track address and a sectoraddress, or a track address, a sector address and an ID, which arearranged in the stated order from the side of the MSB. The linearaddress is incremented by one with increase of the sector number. Theformatter is therefore formed of a simple up-counter.

A predetermined number of bits from the head of the address for eachsector represents a virtual logical track. Since the virtual trackaddress is always the predetermined number of bits, the compatibilitywith conventional optical disk drive devices is improved. For instance,according to the conventional optical disk standard, the PEP region(phase encoding part where the physical properties of the disk or theconditions under which the writing is to be performed are written) has aregion for track addresses of only 16 bits. To be compatible with such astandard, 16 bits from the MSB are taken as the virtual track address.

It may be so arranged that an attribute, which is either an attributeindicating a rewritable area, a write-once area or a read-only area, canbe independently set for each zone. It is then possible to placedifferent types of areas in a single disk, in various combinations, anda disk which best suits to the intended applications can be obtained.

A difference obtained by subtracting the number of parity tracks of eachzone from the number of parity tracks of another zone adjacent to andoutside of each zone is preferably constant. Then, it is possible todetermine the number of the parity tracks in each zone without referringto a table.

Where a rewritable area and a write-once area are both provided in asingle disk, it is preferable that a rewritable area is provided outsideof a write-once area. This improves the overall performance of the disk.because the rewritable are is more frequently accessed than thewrite-once area, and the data transfer is rate is higher in the moreoutward zones.

According to another aspect of the invention, there is provided anoptical disk drive device for use in combination with an optical diskincluding a recording region, physical tracks in said recording regioneach corresponding to one revolution, the recording region being dividedinto a plurality of zones by one or more circular boundary linescentered on the center of the disk, each zone including a plurality oftracks adjacent to each other, wherein an integer number of sectors areprovided in each physical track, the angular recording density is higherin the more outward zones such that the linear recording density issubstantially constant throughout the recording region, and logicaltracks are formed of a predetermined number of sectors, independent ofthe physical tracks, the optical disk drive device determining thelogical track address and the sector address responsive to a linearlogical address by determining the integral quotient and the remainderby dividing the linear logical by the number of the sectors per logicaltrack.

With the above arrangement, conversion from the linear logical addresssupplied from the host device into the logical track and sectoraddresses can be achieved through simple integer calculations andwithout referring to a table, so that the configuration of the drivedevice or the software for implementing the conversion may be simple.

According to another aspect of the invention, there is provided anoptical disk drive device for use in combination with an optical diskincluding a recording region, physical tracks in said recording regioneach corresponding to one revolution, the recording region being dividedinto a plurality of zones by one or more circular boundary linescentered on the center of the disk, each zone including a plurality oftracks adjacent to each other, wherein an integer number of sectors areprovided in each physical track, the angular recording density is higherin the more outward zones such that the linear recording density issubstantially constant throughout the recording region, and logicaltracks are formed of a predetermined number of sectors, independent ofthe physical tracks, wherein a difference obtained by subtracting thenumber of the logical tracks corresponding to each zone from the numberof the logical tracks corresponding another zone adjacent to andradially outside of said each zone is of a constant value, the opticaldisk drive device determining the zone containing the target sector onthe basis of a product of the constant value and the number of thezones.

With the above arrangement, the zone can be determined through simpleinteger calculations and without referring to a table, so that theconfiguration of the device or the software for implementing thedetermination of the zone may be simple.

According to another aspect of the invention, there is provided anoptical disk drive device for use in combination with an optical diskincluding a recording region, physical tracks in the recording regioneach corresponding to one revolution, the recording region being dividedinto a plurality of zones by one or more circular boundary linescentered on the center of the disk, each zone including a plurality oftracks adjacent to each other, wherein an integer number of sectors areprovided in each physical track, the angular recording density is higherin the more outward zones such that the linear recording density issubstantially constant throughout the recording region, and logicaltracks are formed of a predetermined number of sectors, independent ofthe physical tracks, the optical disk further comprising a table forrecording attributes of the respective zones, the attributes indicatingwhether each zone is designated as a rewritable area, a write-once areaor a read-only area, the table being formed in at least one track or inat least one sector, the optical disk device including a means foraltering the attributes of the respective zones.

With the above arrangement, it is possible to alter the rewritable areato a write-once area. Such function is desired where the disk or part ofthe disk is used for storing data that should not be altered withoutspecific permission. It is also possible to alter write-once area to arewritable area.

According to another aspect of the invention, there is provided anoptical disk drive device for use in combination with an optical diskincluding a recording region, physical tracks in the recording regioneach corresponding to one revolution, the recording region being dividedinto a plurality of zones by one or more circular boundary linescentered on the center of the disk, each zone including a plurality oftracks adjacent to each other, wherein an integer number of sectors areprovided in each physical track, the angular recording density is higherin the more outward zones such that the linear recording density issubstantially constant throughout the recording region, and logicaltracks are formed of a predetermined number of sectors, independent ofthe physical tracks, the optical disk including a first part of therecording region designated as a rewritable area and a second part ofthe recording region designated as a write-once area, the optical diskdevice comprising a means for permitting access of only the rewritablearea to a host device, and means for altering an attribute of saidsecond part from the write-once area to the rewritable area and copyingthe data in the first part to the second part while the host device isnot accessing the optical disk.

With the above arrangement, the host device needs only to provided asingle command, e.g., a back-up command. Then, the drive device executesthe back-up command by copying the data from one part of the disk toanother. In the execution of the command, the attributes of the zonesmay be altered before and after copying the data. Moreover, the back-upis achieved within a single disk, so that it is not necessary to back-upthe data using another disk.

The optical disk drive device may further include means for copying thedata in the second part to said first part while said host device is notaccessing the optical disk. The host device needs only to provide asingle command, e.g., a restore command. Then, the drive device executesthe restore command by copying back the data from a write once area to arewritable area.

The optical disk may have recording regions on first and second surfacesopposite to each other. In such a case, it may be desired that therewritable area is formed on one of the surfaces and the write-once areais formed on the other surface. Then, even when the data on one of thesurfaces is destroyed, identical data can be read from the othersurface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the structure of an optical diskaccording to the invention.

FIG. 2 is a plan view showing the structure of the optical disk of FIG.1.

FIG. 3 is a perspective view showing, partially in section, guidegrooves and land parts.

FIG. 4 is a diagram showing the tracks near the boundary of zones.

FIG. 5 is a table showing the format of the disk of Embodiment 1.

FIG. 6 is a partial plan view showing the placement of the guard andtest tracks.

FIG. 7 is a table showing the format of the disk of Embodiment 2.

FIG. 8 is a table showing the format of the disk of Embodiment 3.

FIG. 9 is a table showing an example of the format of the disk ofEmbodiment 3.

FIG. 10 is a table showing another example the format of the disk ofEmbodiment 4.

FIG. 11 is a diagram showing the format of the header field inEmbodiment 5.

FIG. 12 is a table showing the format of the disk of Embodiment 5.

FIG. 13 is a table showing the format of the disk of Embodiment 6.

FIG. 14 is a diagram showing the format of the header field inEmbodiment 6.

FIG. 15 is a diagram showing the optical disk drive device and the hostdevice.

FIG. 16 is a flow chart showing the procedure of the operation of thedrive device during access of a target sector in the optical disk.

FIG. 17 is a functional block diagram showing the optical disk drivedevice having a function of power adjustment.

FIG. 18 is a flow chart showing the procedure for the power adjustment.

FIG. 19 is a table showing the format of the disk of Embodiment 9.

FIG. 20 is a table showing part of the disk structure management table.

FIG. 21 is a diagram showing allocation of the parts of the disk to therespective types of recording regions according to Embodiment 9.

FIG. 22 is a diagram showing allocation of the parts of the disk to therespective types of recording regions according to Embodiment 10.

FIG. 23 is a diagram showing allocation of the parts of the disk to therespective types of recording regions according to Embodiment 11.

FIG. 24 is a diagram showing the optical disk drive device, and itsfunction of altering the attributes of the zones for producing a diskequivalent to a P-ROM disk.

FIG. 25 is a diagram showing the optical disk drive device, and itsfunction of altering the attributes of some only of the rewritable zonesto "write-once".

FIG. 26 is a diagram showing the optical disk drive device, and itsfunction of altering the attributes of the zones during execution of aback-up command.

FIG. 27 is a flow chart showing the procedure of the operation of theoptical disk drive device for executing the back-up command.

FIG. 28 is a diagram showing the optical disk drive device, and itsfunction of altering the attributes of the zones on one surface of thedisk during execution of a back-up command.

FIG. 29 is a diagram showing the optical disk drive device, and itsfunction for restoring data from the write-once area to the rewritablearea.

FIG. 30 is a flow chart showing the procedure of the operation of theoptical disk drive device for executing the restore command.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiment 1

A first embodiment, Embodiment 1, will now be described with referenceto FIGS. 1 to 5. FIGS. 1 and 2 show the structure of an optical disk ofEmbodiment 1. A spiral guide groove is formed on an optical disk 2. Alight spot 3 is formed by focusing a light beam from a light source, notshown, onto a land part 12 between adjacent parts of the guide groove.Each header field 4 includes a sector address field 5 and a trackaddress field 6. The header fields 4 are in the form of pits in the landparts 12 formed by embossment or stamping when the disk is fabricated.That is, the header fields 4 are preformatted. The data fields 7 arewritten magneto-optically. The information in the form of pits in theheader fields 4 and the information magneto-optically recorded in thedata fields 7 are read by means of the same light beam. Each sector 8includes a header field 4 and a data field 7.

Each of the physical tracks 9 corresponds to one revolution of theoptical disk 2. Each physical track 9 is composed of an integer numberof sectors. A plurality of physical tracks adjacent to each other form azone 10a, 10b or 10c. That is, the recording region (user zone) withinthe recording surface of the optical disk 2 is divided into a pluralityof zones by concentric boundary circular lines centered on the center ofthe disk. Each of the physical tracks in the recording region belongs toone of the zones. In the illustrated example, the recording region isdivided into 31 zones (from zone No. 0 to zone No. 30). The outermostzone No. 0 and the innermost zone No. 30 each comprise 741 physicaltracks, while other zones each comprise 740 physical tracks. Theoutermost zone No. 0 has the greatest number of sectors, and the moreinward zones have a smaller number of sectors. The difference of thenumber of sectors between the adjacent zones is at least "one", and is"one" in the illustrated example.

In use, the disk is rotated at a constant angular velocity regardless ofwhich of the zones the read/write head is accessing.

The frequency of the clocks used for recording data in the respectivezone is varied or switched so that it is higher in the more outwardzones, so that the linear recording density is substantially constantthroughout the recording region (user zone) of the disk.

During reading, the frequency of the clocks is also switched when theread/write head is moved from one zone to another zone.

The innermost tracks 11b and the outermost track 11c in the zones 10band 10c have their header field 4-1 and data field 7-2 adjacent to eachother, and have their header fields 4-2 and data field 7-1 adjacent toeach other.

The logical track structure shown in FIG. 5 is arranged in the physicalstructure described above. FIG. 5 shows an example in which each sectorconsists of 1024 bytes. Each logical track is composed of 17 sectors.The marks at the top parts of the respective columns in the table ofFIG. 5 have the following meanings:

ZN: zone number

S/R: the number of sectors per revolution (physical track)

PT/Z: the number of physical tracks in the zone

S/Z: the number of sectors in the zone=S/R×PT/Z

Σ S/Z: the sum of the numbers of the sectors of the zones (from thefirst zone to the zone in question)

LT/G: the number of logical tracks in the revolution group

Δ LT/G: the difference in the number of logical tracks (LT/G) betweenthe revolution group and the revolution group adjacent to and inside ofthe first-mentioned revolution group

S/G: the number of sectors in the revolution group

Σ S/G: the sum of the numbers of sectors in the revolution groups (fromthe first revolution group to the revolution group in question)

DΣ S: the difference between the sum of the numbers of the sectors ofthe zones and the sum of the numbers of sectors of the revolutiongroups=ΣS/G-ΣS/Z

Each revolution group includes a plurality of sectors. Each revolutiongroup corresponds to each zone. The numbers of logical tracks of therespective revolution groups are determined such that the sectorsbelonging to the respective revolution groups are substantially equal tothe number of the sectors in the corresponding zone. As a result, thestarting point and the end point of each revolution group do notnecessarily coincide with the starting point and the end point of thecorresponding zone, and there may be some offset between them. Thedifferences (DΣ S) in the rightmost column in FIG. 5 indicate suchoffsets, that is, the numbers of sectors which are not in thecorresponding zone, but in the next zone. The sectors (12 sectors in theillustrated example) which belong to the last revolution zone, but arenot accommodated in the last zone are formed in a spare region, formedinside of the innermost zone.

The disk with the logical tracks formed as described above, the trackaddress and the sector address written in the header field of eachsector corresponds to the linear logical address supplied from a hostdevice. The term "linear" with respect to the address means that theaddresses are represented by values which are consecutive integers.Accordingly, the sector address and the track address are determinedthrough simple integer calculations. Although the number of sectors perrevolution differs from one zone to another, this need not be takenaccount in the above calculation.

Moreover, the physical location of the sector on the disk can bedetermined from the logical track address and the sector address throughsimple calculation.

Embodiment 2

Another embodiment, Embodiment 2, will next be described with referenceto FIGS. 6 and 7. FIG. 6 illustrates a part of the optical disk ofEmbodiment 2, and FIG. 7 is a table showing a physical track structureof the optical disk of Embodiment 2. As illustrated in FIG. 6, in thevicinity of the boundary of adjacent zones, at least one physical track14, 15 of each of the adjacent zones are designated as guard tracks,which the user cannot use for recording data. In addition, at least onephysical track 16 in each zone is designated as a test track, which theuser cannot use for recording data. In the illustrated example, theinnermost physical track in each zone is designated as a guard track 14,an outermost physical track is designated as the test track 16, and thephysical track next to the outermost guard track 16 is designated asanother guard track 15.

The guard tracks 14 and 15 are for avoiding crosstalk near the boundarybetween the adjacent zones. The guard tracks are assigned addressesindependent of the addresses of the data recording sectors, and theaddresses of the guard tracks are beyond the range of the addressesassigned to the sectors for recording data. This will ensure that theguard tracks are not accessed during recording or reading data, and theguard tracks are therefore not used for recording data.

The test track 16 is used for adjustment of the recording power. Forinstance, when the drive device is turned on, test data is recorded onthe test track, with a given recording power, and is then reproduced,and the error occurrence rate is determined. The recording power is thenvaried in accordance with the determined error rate, and the recordingis again made with the varied recording power. The above process isrepeated until the error rate becomes sufficiently low. The recordingpower is thereby optimized.

Designating the physical track between the guard tracks 14 and 15 in thevicinity of each boundary between zones as the test track 16 isadvantageous because, with such an arrangement, even when an excessivepower is used for recording in the test track this does not affect thetracks used for recording.

However, any other track may alternatively be designated as the testtrack, as mentioned above.

The test tracks 16 are assigned addresses independent of the addressesof the data recording sectors, and the addresses of the test tracks arebeyond the range of the addresses assigned to the sectors for recordingdata. This will ensure that the guard tracks are not accessed duringrecording or reading data, and the guard tracks are therefore not usedfor recording data.

The tracks other than the guard tracks and the test track are used forrecording data, and each logical track is formed of 17 sectors. Thenumbers of the logical tracks in the respective revolution groups aredetermined so that the difference in the number of the logical tracksbetween the adjacent revolution groups is a constant value, which in theillustrated example is "43". With such an arrangement, the number of thelogical tracks can be determined through simple calculation on integers,and management using a table or the like is unnecessary.

FIG. 7 shows the logical track structure of Embodiment 2. It is similarto that of FIG. 5. However, the number of the physical tracks in each ofthe zones No. 0 to No. 30 is 740, which is the same as the number oflogical tracks in each of the other zones.

In FIG. 7, the marks which are at the top parts of the respectivecolumns and which are identical to those in FIG. 5 have the samemeanings as those in FIG. 5. "G+T" in FIG. 7 denote the number ofsectors in the guard tracks and the test track in the zone.

Embodiment 2 has an advantage over Embodiment 1 with regard to thefollowing points: First, in Embodiment 1, the end point of the lastlogical track in each revolution group does not coincide with the endpoint of the zone, and some sectors are in the next zone, and the numberof such sectors in the next zone is not constant. In such a case, theswitching of the clocks must be controlled in the logical track. It istherefore necessary to perform management over substitution (foraccessing the spare sectors in place of defect sectors), and themanagement over control related to the actual physical arrangement(e.g., the switching of the clocks). Secondly, crosstalk betweenadjacent tracks may occur near the zone boundaries. Thirdly, adjustmentof power using a test track cannot be made. Furthermore, there is norule or regularity on the number of logical tracks in the respectiverevolution groups, so that it is necessary to provide a table storingthe number of logical tracks in each revolution group, and this tableneeds to be referred to for the conversion from the logical address tothe physical address.

The logical track structure shown in FIG. 7 solve the problem discussedabove. The logical tracks of each revolution are all accommodated in thecorresponding zone. Moreover, by the provision of the guard tracks, thecrosstalk at the zone boundary is eliminated. Furthermore, the recordingpower can be adjusted using the test track. In addition, since thedifference in the number of logical tracks between adjacent revolutiongroups is constant, conversion from the logical address to the physicaladdress can be achieved by simple calculation, and does not require atable.

Embodiment 3

Another embodiment, Embodiment 3, will next be described with referenceto FIG. 8. It is similar to Embodiment 2, but differs from it in thefollowing respects:

With the format of the logical track of Embodiment 2, the number ofsectors remaining in each revolution group after assigning the requirednumber of tracks for data recording differs from one track to another.As a result, it is necessary to record the number of the remainingsectors in a table and refer to it in determining the physical location.

FIG. 8 shows the logical track structure for solving the above problem.The marks which are at the top parts of the respective columns and whichare identical to those in FIG. 5 or 7 have the same meanings as those inFIG. 5 or 7. "DUM" denotes the number of sectors remaining afterassigning the logical tracks, "Δ DUM" denotes the difference in DUMbetween adjacent zones, and "RES" denotes the sum of DUM and G+T.

As seen from FIG. 8, the difference in the number of the logical tracks,LT/G, between adjacent revolution groups is of a constant number, e.g.,43, and the three physical tracks are reserved for the guard tracks andthe test track, and the number of the remaining sectors, DUM, is of aconstant number, e.g., "6" in the illustrated example. Accordingly, thephysical location of the sector can be determined through calculationusing a formula in which the number of the remaining sectors, DUM, isincorporated, and it is not necessary to provide a table storing thenumber of remaining sectors of the respective revolution groups, whichwere necessary when the number of the remaining sectors differ from onerevolution group to another.

Embodiment 4

Another embodiment, Embodiment 4, will next be described with referenceto FIGS. 9 and 10. This embodiment is identical to Embodiment 2, exceptthat the number of the physical tracks per revolution group and thenumber of the revolution groups within the recording region of the diskdiffer from those of Embodiment 2.

The format of the logical tracks of Embodiment 3 solved the problems ofEmbodiments 1 and 2, and the number of the remaining sectors is apositive number so that the logical tracks do not bridge adjacent zones.Moreover, the physical location of a target sector can be determinedthrough calculation on integers, without referring to a table. However,the remaining sectors in which no data is recorded exist. The capacityof the disk is not fully utilized.

FIGS. 9 and 10 shows logical track structures for solving the aboveproblems of Embodiment 3. FIG. 9 shows a case in which each sectorconsists of 1024 bytes, while FIG. 10 shows a case in which each sectorconsists of 512 bytes. In each of FIGS. 9 and 10, the total number ofsectors in each revolution group corresponds to an integer number oflogical tracks, and the difference in the number of logical tracksbetween adjacent revolution groups is a constant number, which is "176"in FIG. 9, or "54" in FIG. 10.

In the illustrated examples no guard and test tracks are provided.However, they may be provided in the same way as in Embodiment 3.

Embodiment 5

Another embodiment, Embodiment 5, will next be described with referenceto FIGS. 11 and 12. In this embodiment, each sector consists of 1024bytes. The structure of the disk is identical to that shown in FIGS. 1to 3, but the header field of each sector differs from that of FIG. 1.That is, as shown in FIG. 1, it has two header sections 4a and 4b. Eachof the header sections 4a and 4b comprises a track address field 6, asector address field 5 and an ID field 21. Identical addresses arerecorded in the track address fields 6 and the sector address fields 5in the two header sections 4a and 4b. The addresses indicate the sectorof which the header sections 4a and 4b form a part. The identicaladdresses are written in duplicate in order to improve the reliability.A binary "0" is written in the ID field 21 in the first header section4a, and a binary "1" is written in the ID field 21 in the second headersection 4b. The ID field 21 in each header section 4a or 4b therebyidentifies the header section, i.e., whether it is the first headersection or the second header section in each sector.

FIG. 12 shows the logical track structure. The marks which are at thetop parts of the respective columns and which are identical to those inFIGS. 5, 7 or 8 have the same meanings as those in FIGS. 5, 7 and 8."S/LT" denotes the number of sectors per logical track. The arrangementof the tracks as shown is generally identical to that of FIG. 5 butdiffers from that of FIG. 5 in the following respects: First, the numberof zones is not 31 as in FIG. 5, but is 30. Each zone has 752 physicaltracks. Each logical track has 2^(n) sectors. In the illustrated examplen=4 so that 2^(n) =2⁴ =16 sectors.

As illustrated in FIG. 11, the track address field 6 is formed of 16bits, and is used to represent an address value of from "0" to "22560",and the sector address field 5 is formed of 4 bits and is used torepresent ad address value of from "0" to "15".

As has been described, since the track address is represented by 2^(n)or 16 bits, calculation of the track address is easy.

Embodiment 6

Another embodiment, Embodiment 6, will next be described with referenceto FIGS. 13 and 14. Each sector consists of 1024 bytes, like Embodiment5. As illustrated in FIG. 13, each of the zones Nos. 0 to 29 comprises768 physical tracks 10, and each logical track consists of 128 sectors.Addresses are written in duplicate. FIG. 14 shows header sections 4a and4b. The track address 6 is composed of 16 bits and is used to representa value of from "0" to "23040". The sector address 5 is composed of 7bits and is used to represent a value of from "0" to "127". The ID fieldis composed of a single bit and is used to represent "0" or "1".

With the arrangement of the logical tracks described above, the trackaddress and sector address read from the disk correspond directly (asis) to the linear logical address from a host device, and the actualtrack and sector addresses can be determined through simple intergarcalculations integers. Moreover, any difference in the number of sectorsper revolution need not be taken account of.

Embodiment 7

Another embodiment, Embodiment 7, will next be described with referenceto FIGS. 15 and 16. This embodiment relates to an optical disk drivedevice, and in particular to its operation for accessing the targetsector on an optical disk having been loaded onto the drive device. FIG.15 shows an optical disk drive device 31 used for writing in and readingfrom optical disks, and a host device 32 connected to the optical diskdrive device 31. The optical disk 2 is actually loaded in the opticaldisk device 31 but is shown to be placed outside the device 31 for thesake of convenience of illustration. The host device 32 providescommands for writing on or reading from the optical disk 2, togetherwith the designation of the address on or from which the writing orreading is to be conducted. The address is a linear address.

Upon receipt of such a command, the drive device 31 performs theoperation for seeking the track in which the sector corresponding to thedesignated address is located. The operation for writing and reading isknown, and its description is omitted.

FIG. 16 shows the seek operation. The drive device 31 first reads thelogical track address of the currently-accessed track, i.e., the logicaltrack which the read/write head of the optical disk drive device is nowconfronting or accessing (102). Then, on the basis of the track numberhaving been read, the zone to which the currently-accessed logical trackbelongs, is identified, that is the zone number is determined (104).Then, the physical location of the logical track of which the addresshas been read is determined (106). Then, the linear logical address fromthe host device 32 is converted into the logical track address (108).Then, the zone number of the zone to which the target logical trackbelongs is determined (110). Then, the physical location of the targetsector is determined (112). Then, the number of physical tracks whichlie between and the currently-accessed track and the target position,i.e., which have to be traversed for the seek operation, is determined,taking into consideration the zone number (114). Then, the head is movedfor traversing the number of physical tracks, that is determined to liebetween the currently-accessed track and the target position (116). Theabove operation is repeated until the target track is reached (118).

When the head arrives at the target track, the addresses in therespective sectors are read, to find out the target sector.

Using the optical disks of the above embodiments exhibit advantages inthe above-described seek operation. For instance, if a disk of any ofEmbodiments 1, 2 an 3 is used, the conversion at the step 108 isaccomplished by simple calculation: That is, the logical track addressAt and the logical sector address As are given as the integral quotientand the remainder of the division:

    A.sub.L /(S/LT)

wherein S/LT is the number of sectors per logical track, and A_(L) isthe linear logical address from the host device. Accordingly, the tablefor the conversion of the address is not necessary and the configurationof the drive device and/or the software for implementing the seekoperation is simplified.

An additional advantage obtained if a disk of Embodiment 2 is used isthat the determination of the zone number at the step 104 and at thestep 110 is made using the following relationship:

    ZN×{LT/G.sub.ZN=0 +(LT/G.sub.ZN=0 -ΔLT/G×ZN)}/2=17×At+(the number of remaining sectors as stored in the table).

where LT/G_(ZN=0) is the number of the logical tracks in the zone No. 0.The table needs only to store the number of the remaining sectors, whichare relatively small figures. Therefore, the required size of the tableis small, and the configuration of the device or the software forimplementing the seek operation is simplified.

An additional advantage obtained if a disk of Embodiment 3 is used isthat the determination of the zone number at the step 104 and at thestep 110 is made using the following relationship:

    ZN×{LT/G.sub.ZN=0 +(LT/G.sub.ZN=0 -ΔLT/G×ZN)}/2=17×At

Thus, the correction using the number of remaining sectors as stored inthe table is not required. IT is therefore not necessary to provide sucha table for the determination of the zone number at the step 104 or 110.

Embodiment 8

Another embodiment, Embodiment 8, will next be described with referenceto FIGS. 17 and 18. This embodiment relates to an optical disk drivedevice, and in particular to its operation for adjusting the power ofthe laser beam used for writing. Such adjustment is conducted prior tothe actual writing, e.g., when the drive device is turned on. FIG. 17 isa block diagram showing the function of the drive device. Asillustrated, the drive device 31, which may be connected to a hostdevice as shown in FIG. 15, comprises a controller 33 provided with aCPU, a ROM and a RAM, a recording circuit 34, a laser controller 35, aread/write head 36 with a built-in semiconductor laser, a reproducingcircuit 37, and an evaluation circuit 38. The controller 33 isresponsive to commands from the host device 32 for sending controlsignals to various parts of the device 31 to conduct signals to variousparts of the device 31 to conduct the writing power adjustment. Itoutputs a designation of the initial value of the writing power. Therecording circuit 34 conducts recording of test data responsive to thecontrol signals from the controller 33. That is, it provides the testdata used for the recording for the purpose of power adjustment. Thelaser controller 35 modulates the test data supplied from the recordingcircuit 34 and supplies the modulated test data to the read/write head36. It sets the laser power to the initial value designated by thecontroller 33. The read/write head 36 records the test data on the disk2 with the power that is set by the laser controller 35. The read/writehead 36 also reads the test data having been recorded. The reproducingcircuit 37 demodulates the test data read by the read/write head 36. Theevaluation circuit 38 evaluates the fidelity of the reproduced data withrespect to the test data output from the recording circuit 34. That is,it determines the error rate in the reproduced data, and evaluates thequality of reproduced data. On the basis of the evaluation, thecontroller 33 varies the set value of the writing power. The abovedescribed steps are repeated to obtain the optimum writing power.

FIG. 18 shows the above-described procedure for determining the optimumwriting power. First an initial value of the writing power is set (202),and the writing is conducted with the initial value (204). Then, thetest data having been written is reproduced (206). Then, the quality ofthe reproduced data is evaluated (208). If the quality is foundsatisfactory, the process is terminated. If not, judgement is madewhether the power is too large or too small (210). If the power is foundtoo large, the set value of the power is lowered (212). If the power isfound too small, the set value is raised (214). The, the process isreturned to the step 204. The above-described steps are repeated untilthe quality of the reproduced data is found satisfactory.

Embodiment 9

Another embodiment, Embodiment 9, will next be described with referenceto FIG. 19. The structure of the disk of this embodiment is generallyidentical to that of Embodiment 1. However, as will be detailed below,the attributes of the zones can be set independently of each other. Theterm "attribute" as used herein refer to an indication or designationthe type of the recording area, i.e., it indicates whether the area inquestion is of a read/write type, a write-once type or a read-only type.

FIG. 19 shows the logical track structure of the disk of thisembodiment. Each sector consists of 1024 bytes and each logical trackconsists of 17 sectors. The marks which are at the top parts of therespective columns and which are identical to those in FIGS. 5, 7, 8 and12 have the same meanings as those in FIGS. 5, 7, 8 and 12. "FLT"denotes the address of the first logical track in the zone. "LT" denotesthe numbers of the logical tracks for recording data, spare tracks orparity tracks in the zone. "TEST" denotes the number of the test tracksin the zone. "PAR" denotes the numbers of the parity tracks in the zone.The parity tracks are used to record parity symbols when the zone isdesignated as the O-ROM type.

As shown in FIG. 19, the recording region is divided into 30 zones, zoneNos. 0 to 29. Each zone consists of 748 physical tracks. The number ofthe logical tracks in each zone can be determined by dividing the numberof sectors in the zone by 17. The number of the parity tracks variesfrom 144 to 86 with the increase of the zone number from 0 to 29, thedifference between the adjacent zones being two. To determine the numberof the parity tracks for each zone, it is only necessary to decrement bytwo. Such determination can be made by simple interger calculations andno table need be referred to for this calculation.

FIG. 20 shows part of the disk structure management table of the disk ofEmbodiment 9, in which each sector comprises 1024 bytes. The diskstructure management table is provided at the head of the defectmanagement region (at the head of the user zone, or at the first sectorin the first (No. 0) zone.

The 0-th to 21st bytes in the table are for information relating todefect management, and are not directly relevant to the invention, sothat their illustration and description are omitted. The 22nd to 51stbytes are for identifying the type of each of the zones Nos. 0 to 20.The "type" as meant here is either the R/W (read/write or rewritable)type, the WO (Write-once) type or the O-ROM (fully embossed orread-only) type, as described above. The value "01" in the row of eachbyte indicates that the corresponding zone is of the R/W type, "02" inthe row of each byte indicates that the corresponding zone is of theO-ROM type, and "03" in the row of each byte indicates that thecorresponding zone is of the WO type. "/" between "01", "02" and "03"signifies "or".

When the disk is of the R/W type, the 22nd to 51st bytes are all set to"01". When the disk is of the WO type, the 22nd to 51st bytes are allset to "03". When the disk is of the O-ROM type, the 22nd to 51st bytesare all set to "02". When the disk is of the P-ROM type (i.e., the diskcomprises one or more zones of the R/W type and one or more zones of theO-ROM type), the bytes corresponding to the R/W type zones are set to"01", while the bytes corresponding to the O-ROM type zones are set to"02".

When the disk is of the R/W+WO type (i.e., the disk comprises one ormore zones of the R/W type and one or more zones of the WO type), thebytes corresponding to the R/W type zones are set to "01", while thebytes corresponding to the WO type zones are set to "03".

When the disk is of the WO+O-ROM type (i.e., the disk comprises one ormore zones of the WO type and one or more zones of the O-ROM type), thebytes corresponding to the WO type zones are set to "03", while thebytes corresponding to the O-ROM type zones are set to "02".

When the disk is of the R/W+WO+O-ROM type (i.e., the disk comprises oneor more zones of the R/W type, one or more zones of the WO type, and oneor more zones of O-ROM type), the bytes corresponding to the R/W typezones are set to "01", the bytes corresponding to the WO type zones areset to "03", and the bytes corresponding to the O-ROM type are set to"02".

Each zone can be set to any type independently of other zones.

In the past, only four types of disks, i.e., the R/W type, the WO type,the O-ROM type and the P-ROM type, were available. According to theabove embodiment, three additional types, i.e., the R/W+WO type, theWO+O-ROM type, and the R/W+WO+O-ROM type are available. In all, seventypes are thus available.

Moreover, in the prior art P-ROM type disk, the disk is divided into twoparts by a circular boundary line, and the zone or zones outside of theboundary line is of one of the R/W type and the WO type, and the zone orzones inside of the boundary line is of the other of the R/W type or theO-ROM type. In contrast, according to this embodiment, each of the zonescan be set to any type freely.

Embodiment 10

Another embodiment, Embodiment 10, will next be described with referenceto FIG. 21. As described earlier, the disk is rotated at a constantangular velocity in use, and the frequency of the clocks used forrecording and reading is switched depending on the zone in which theread/write head is accessing. Where the disk contains the R/W type zoneor zones, the WO type zone or zones, and the O-ROM type zone or zones,the R/W zone or zones are placed in the outermost part of the disk, theO-ROM type zone or zones are placed in the innermost part of the diskand the WO type zone or zones are placed in the intermediate part of thedisk, as illustrated in FIG. 21. The reason is that the data transferrate is higher in the more outward zones, so that the more outward zonesare assigned for the type of the recording zones which are morefrequently accessed. In the above described situation, the R/W type ismost frequency accessed because three types of operations, i.e.,reading, writing and erasing operations are performed, so that theoutermost part of the disk is allocated to the R/W type zones. The WOtype zone or zones are accessed more frequently than the O-ROM typebecause the former additionally permits the writing operation, althoughonly once. The W/O type zones are therefore placed more outward than theO-ROM type zones.

Embodiment 11

Another embodiment, Embodiment 11, will next be described with referenceto FIG. 22. The disk is basically of the same structure as that of theEmbodiment 10, but it only contains the R/W type zone or zones and theWO type zone or zones. The R/W type zone or zones are placed moreoutward than the W/O type zone or zones, because R/W zones are morefrequently accessed.

Embodiment 12

Another embodiment, Embodiment 12, will next be described with referenceto FIG. 23. The disk is basically of the same structure as that of theEmbodiment 10, but it only contains the WO type zone or zones and theO-ROM type zone or zones. The WO type zone or zones are placed moreoutward than the O-ROM type zone or zones, because the former permitswriting operation, although only once.

Embodiment 13

Another embodiment, Embodiment 13, will next be described with referenceto FIG. 24. This embodiment relates to an optical disk drive device 31which alters the attributes of the zones in the manner described below.The drive device 31 is connected to a host device 31 by an interfacesuch as SCSI. The optical disk 2 is loaded in the drive device 31, butis shown to be placed outside the drive device 31 for convenience ofillustration.

In this embodiment, the recording region is entirely of the R/W typewhen fabricated. However, the area denoted as "vacant" is initiallyinaccessible. The drive device 31 has the function of altering theattributes of the zones written in the management table. This functionis performed by executing a command A. When the drive device 31 receivesthe command A from the host device 32, the attributes of the zonesdesignated by the command A are altered to "WO". At the same time, thezones which have been inaccessible are altered to accessible R/W zones(as indicated by B). The zones having been altered to WO type permitswriting of data once, and after that the data cannot be altered. That isthis part is now like ROM type part. The R/W part, which have beenaltered from inaccessible part, now permits writing and reading. Thus, adisk having the same function as P-ROM is obtained.

The alteration of the attributes can be made by the user, and theattributes having been altered to WO may be returned to R/W.

An advantage of the disk of this embodiment is lower cost in someapplications. P-ROM disks with their ROM part formed by embossment isexpensive where the number of the disk produced at the same time islimited because of the relatively high cost of fabricating the originaldisk. In contrast, the disks formed in the above manner are lessexpensive and yet have the same function as P-ROM disks having embossedpart.

Embodiment 14

Another embodiment, Embodiment 14, will next be described with referenceto FIG. 25. This embodiment also relates to an optical disk drive device31 capable of altering the attributes of the zones. In Embodiment 13,the accessible R/W zones are all changed to WO zones. In Embodiment 14,the attributes of only such zones which are designated by a command Care altered, e.g., to WO (as indicated by D). Such alteration is desiredfor instance to prevent alteration of data only in certain zones.

Embodiment 15

Another embodiment, Embodiment 15, will next be described with referenceto FIG. 26. This embodiment also relates to an optical disk drive devicecapable of altering the attributes of the zones and executing a back-upcommand. Description of the parts identical to those in FIG. 24 isomitted. The attributes of the zones are written in the management table41. As illustrated in FIG. 26, alternate zones are designated as R/Wzones and intervening zones are designated as WO zones. The totalcapacity of the WO zones is about the same as the total capacity of theR/W zones.

A procedure for control for executing a back-up command is shown in FIG.27. First, when the drive device 31 receives the command from a hostdevice (302), it determines whether it is an inquiry on capacity, aread/write command, or a back-up command (304). If it is the inquiry,the an answer indicating the capacity of the R/W area is sent to thehost device (306). If it is the read/write command (308), judgement isthen made whether the read/write head is accessing an R/W area (310),and if the answer is affirmative, the command is executed (312). If itis the back-up command (314), a message indicating that the execution ofthe command is completed is sent to the host device (316), and the datain the R/W area is copied into the WO area (320), when it is found thatthe host device is not accessing. If necessary, the attributes of thezones are altered to "R/W" (318) prior to the copying, and returned to"WO" (322) after the copying. In FIG. 26, the back-up command isindicated by E, and the alteration of the attributes in the table isindicated by F and H, and the copying of the data is indicated by G.

Embodiment 16

Another embodiment, Embodiment 16, will next be described. Thisembodiment also relates to an optical disk drive device capable ofaltering the attributes of the zones. The embodiment is similar toEmbodiment 15. The optical disk 2 permits recording on both sides orsurfaces. The drive device 31 has the function of reading from thewiring on both surfaces of the disk without turning the disk 2 upsidedown. A first surface is entirely an R/W area, while a second surface isentirely a WO area. By the same procedure shown in FIG. 27, the back-upcommand is executed. That is, responsive to a back-up command (I), theattributes of the second surface is altered to R/W (J), the data on thefirst surface is copied to the second surface (K), and the attributes ofthe second surface is returned to (L). Because the second surface isreturned to WO after the copying, the data having been copied into thesecond surface is not destroyed by a device which does not have thefunction of altering the attribute.

Embodiment 17

Another embodiment, Embodiment 17, will next be described with referenceto FIGS. 29 and 30. This embodiment also relates to an optical diskdrive device 31 capable of altering the attributes of the zones.Description of the parts identical to those in FIGS. 26 and 28 isomitted. When the drive device 31 receives a restore command (M) fromthe host device 32 (402), it sends a message back to the host device 32indicated the execution of the restore command is completed (404), andcopies the data in the WO area to the R/W (406).

The invention has been described with reference to the illustratedembodiments. However, various modifications are possible withoutdeparting from the scope of the invention.

What is claimed is:
 1. An optical disk comprising:a recording regionhaving a plurality of sectors with a predetermined length, the sectorsbeing arranged on a spiral or a concentric circle formed on therecording region; wherein the sectors are sequentially numbered asaddresses using binary digits, the addresses are included in a headerfield of each of the sectors, and a logical track, as a unit for anaccess operation, is formed by a series of 2^(n) sectors, where n is aninteger.
 2. An optical disk according to claim 1, wherein the address ofeach of the sectors is arranged in the header field which includes alogical track address and a sector address, the logical track addressbeing positioned before or after the sector address.
 3. An optical diskaccording to claim 1, wherein a predetermined number of bits from abeginning of the address for each sector represents the logical trackaddress.
 4. An optical disk according to claim 1, wherein apredetermined number of bits from an end of the address for each sectorrepresents an order of the sector in the logical track.
 5. An opticaldisk according to claim 1, wherein each of the sectors includes in theheader field 2^(m) sector address fields in which a sector address iswritten, where m is an integer.
 6. An optical disk drive device for usewith an optical disk including a recording region, and a plurality ofsectors with a predetermined length, the sectors being arranged on aspiral or a concentric circle formed on the recording region;wherein thesectors are sequentially numbered as addresses by using binary digits,the addresses are included in a header field of each of the sectors, anda logical track, as a unit for an access operation, is formed by aseries of 2^(n) sectors, where n is an integer; and the optical diskdrive device determines the logical track address by extracting apredetermined number of bits from a beginning of the address for eachsector.
 7. An optical disk drive device for use with an optical diskincluding a recording region and a plurality of sectors with apredetermined length, the sectors being arranged on a spiral or aconcentric circle formed on the recording region;wherein the sectors aresequentially numbered as addresses using binary digits, the addressesare included in a header field of each of the sectors, and a logicaltrack, as a unit for an access operation, is formed by a series of 2^(n)sectors, where n is an integer; and the optical disk drive devicedetermines an order of the sector in the logical track by extracting apredetermined number of bits from an end of the address for each sector.